3,911 research outputs found
Dichlorido{[2-(diphenylÂphosphino)phenylÂiminoÂmethÂyl]ferrocene-κ2 N,P}platinum(II) dichloroÂmethane hemisolvate
In the title compound, [FePt(C5H5)(C24H19NP)Cl2]·0.5CH2Cl2, the PtII atom adopts a distorted square-planar geometry defined by one P atom and one N atom from the bidentate [2-(diphenylÂphosphino)phenylÂiminoÂmethÂyl]ferroÂcene ligand and two Cl atoms. Two disordered dichloroÂmethane solvent molÂecules are each 0.25-occupied on a twofold rotation axis
2-(4-ChloroÂphenÂyl)-5-(3,4-dimethoxyÂphenethÂyl)-6,7-dihydroÂpyrazolo[1,5-a]pyrazin-4(5H)-one
In the title compound, C22H22ClN3O3, the dihedral angles between the planes of the benzene rings and the pyrazole ring are 16.05 (10) and 84.84 (10)°. The conformation of the six-membered heterocyclic ring is close to a screw-boat. The crystal packing is stabilized by weak interÂmolecular C—H⋯O interÂactions and is also consolidated by C—H⋯π interÂactions
Spectrum of the S-wave fully-heavy tetraquark states
In present work, spectrum of the -wave fully-heavy tetraquark states
(), i.e., , ,
/, / ,
/, and are
systematically investigated within an nonrelativistic constituent quark model,
in which the Instanton-induced and one-gluon-exchange interactions are taken
into account as the residual spin-dependent hyperfine interaction. Our results
show that the states with and components
could be located around MeV and MeV, respectively. Based on
our calculations, the new state observed by LHCb may be not a ground
tetraquark state, while it could be an orbitally or radially
excited state of system. On the other hand, the recently
reported state by CMS and ATLAS can be explained as a ground
tetraquark state with spin-parity .Comment: Version to appear in Eur. Phys. J.
Bis[1,1′-(1,3-phenylÂenedimethylÂene)di(1H-imidazol-3-ium)] β-octaÂmolybdate
In the title compound, (C14H16N4)2[Mo8O26], the β-octaÂmolybdate anion is centrosymmetric. N—H⋯O hydrogen bonds link the diimidazolium cations and the polyoxidoanions into a chain structure along [100]. π–π interÂactions between the imidazole rings and between the imidazole and benzene rings [centroid–centroid distances = 3.611 (2) and 3.689 (3) Å, respectively] connect the chains
Effects of low-temperature stress on intestinal structure, enzyme activities and metabolomic analysis of juvenile golden pompano (Trachinotus ovatus)
Water temperature plays a crucial role in the growth, survival, and reproduction of fish species, as they make up the majority of aquatic fauna. In this study, the effects of low temperature were studied on the functional state of juvenile golden pompano (Trachinotus ovatus) under low-temperature stress. The study was conducted at 28°C in the control group and 18°C in the cold group for 14 d to determine the intestinal tissue, digestive and antioxidant enzyme activities, and metabolites of juvenile fish. The results showed that: (1) the swelling degree of the muscle layer deepened and was congested with a longer low-temperature stress period. The folds were sparse, from slight swelling to shedding and deformation. The intestinal mucosa was necrotic and had vacuoles, and the number gradually increased. Serious erosion of the villi occurred. (2) The specific activities of digestive enzymes showed a downward trend. (3) The intestinal superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, and glutathione peroxidase (GSH-Px) activity showed an upward trend. The intestinal catalase (CAT) activity showed a downward trend. (4) Compared with the control group, there were 28 metabolites in the cold group showing significant differences, among which Z, 11Z, 14Z-eicosatrienoic acid, stearic acid, and adrenic acid showed an upward trend. In contrast, spermidine and uracil showed a downward trend. Among the enriched metabolic pathways, the main differential pathways were unsaturated fatty acid biosynthesis, fatty acid biosynthesis, linoleic acid metabolism, pyrimidine metabolism, and β-alanine metabolism. According to metabolomic analysis, under low-temperature stress, the fish body improved the synthesis of unsaturated fatty acids and saturated fatty acids to adapt to a low-temperature environment and consumed spermidine to improve its immune ability to clear the peroxide generated by the synthesis of unsaturated fatty acids in the body so that the cells were protected from oxidative damage. After 14 days, low-temperature stress affected metabolites and enzyme activity indices in juvenile golden pompano. Low-temperature stress causes changes in intestinal antioxidants and digestive enzymes and damage intestinal tissues. As a result of this exploration of how low temperatures affect the juvenile golden pompano, the foundation is laid for future studies, such as the molecular mechanisms of low-temperature adaptation in fish species
Experimental warming causes mismatches in alpine plant-microbe-fauna phenology
Long-term observations have shown that many plants and aboveground animals have changed their phenology patterns due to warmer temperatures over the past decades. However, empirical evidence for phenological shifts in alpine organisms, particularly belowground organisms, is scarce. Here, we investigate how the activities and phenology of plants, soil microbes, and soil fauna will respond to warming in an alpine meadow on the Tibetan Plateau, and whether their potential phenological changes will be synchronized. We experimentally simulate an increase in soil temperature by 2-4 degrees C according to future projections for this region. We find that warming promotes plant growth, soil microbial respiration, and soil fauna feeding by 8%, 57%, and 20%, respectively, but causes dissimilar changes in their phenology during the growing season. Specifically, warming advances soil faunal feeding activity in spring and delays it in autumn, while their peak activity does not change; whereas warming increases the peak activity of plant growth and soil microbial respiration but with only minor shifts in their phenology. Such phenological asynchrony in alpine organisms may alter ecosystem functioning and stability.Phenological shifts driven by climate change are well-studied in plants and aboveground animals, but scarcely in belowground biota. Here, the authors show that soil warming causes phenological mismatches between plants, soil microbes and soil microarthropods in an alpine meadow
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